A kind of preparation method of positive electrode material of lithium ion battery and precursor thereof

Abstract

The invention provides a preparation method of a positive electrode material of a lithium ion battery and a precursor thereof. The metal salt solution, precipitating agent and complexing agent are added to the sedimentation reactor with bottom liquid and overflow pipe for continuous reaction. The reaction slurry is classified through the hydrocyclone, and the fine powder is passed through the hydrocyclone. The overflow port of the hydrocyclone enters the thickener to increase the solid content of the slurry, and then flows back into the precipitation reactor to continue to crystallize and grow. The slurry that removes the fine powder enters the aging reactor with stirring through the underflow port of the hydrocyclone, and then After filtering, washing, drying, and sieving, a precursor is obtained; then the precursor is mixed with a lithium source, sintered, crushed, and sieved to obtain a positive electrode material. The method can efficiently and stably eliminate the fine powder of positive electrode materials and precursors, and the particle size distribution width of the product is moderate, and the comprehensive performance is excellent; and the process is simple, the reaction system is easy to control, the production capacity is high, the degree of automation is high, and the production cost is low. large-scale industrial production.

Description

technical field [0001] The invention relates to a preparation method of a positive electrode material of a lithium ion battery and a precursor thereof, in particular to a preparation method of eliminating the fine powder of a positive electrode material of a lithium ion battery and a precursor thereof, and belongs to the technical field of lithium ion batteries. Background technique [0002] Lithium-ion battery is the secondary battery with the best comprehensive performance at present. Due to its advantages such as high specific energy, long cycle life, small self-discharge, and no memory effect, it is widely used in portable electric tools, electric vehicles, mobile phones, notebook computers, and tablets. Computers, camcorders, military equipment, peak shaving energy storage and distributed energy storage and other fields. [0003] In recent years, as people have higher and higher requirements on the specific capacity of lithium-ion batteries, their cycle performance and ...

AI Technical Summary

Problems solved by technology

[0005] Usually, the method of eliminating the small particles and fine powder of positive electrode materials in the industry is to classify the dry powder of positive electrode materials and precursors through grading equipment, or to produce precursors by batch synthesis, but the above methods have relatively large shortcomings. The first method The small particles and fine powder after classification can only be scrapped as unqualified materials, resulting in low yield of positive electrode materials and high production costs; the particle size distribution of the precursor obtained by the second method is too narrow, resulting in low compaction density of the positive electrode material. Affects the energy density of the battery, and the batch-to-batch production of precursors has poor stability

Chinese patent CN105731553A discloses a crystal cluster-like ternary cathode material precursor and its preparation method. In the patent, a batch synthesis method is used to improve the precipitation conditions of the ternary precursor. The obtained precursor has a spherical structure, but the particle size distribution is too high. Narrow, not conducive to improving the compaction density of the positive electrode material

Chinese patent CN103943847B discloses a method for preparing a nickel-cobalt-manganese ternary material precursor. In the patent, the dry powder of the prepared ternary material precursor is passed through a 600-mesh sieve, and the small particle size sieve material obtained by sieving is prepared into a suspension The turbid liquid is added to the reaction kettle for re-reaction. Although this method can remove part of the fine powder, the efficiency is low and the effect is poor, and because the fine powder returned to the synthesis kettle has been oxidized, the particles will be stratified when it is synthesized again. The product performance will deteriorate

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